What is the difference between weather and climate?

Two clouds walk into a room. One is in a terrible mood today — gray, grumbly, ready to dump rain on your picnic. The other shrugs and says, "Eh, around here it's usually like this." One of these clouds is talking about weather. The other is talking about climate. They are not the same thing, and the difference is one of the most useful ideas you'll ever borrow.
Weather is what's happening right now, outside, today. Is it raining? Windy? Hot enough to fry an egg on the sidewalk? Cold enough to see your breath? That's weather. It's a mood. It can flip from sunny to stormy before lunch, and it almost never asks your permission first.
